http://www.caa.co.uk/News/UK-aviation-encouraging-more-people-with-a-disability-to-fly-but-four-airports-told-they-must-improve/

A couple of years ago my sister needed wheelchair service at Gatwick as she had a foot in plaster and couldn't walk more than a short distance , I personally thought the intial service was quite poor and a bit slapdash , but once airside the service improved and was actually done very well .

Saw this report and it's not really that good that the 1st and 3rd busiest airports are considered poor in their service and in my own experience I didn't think the service in the 2nd busiest was that great overall